A part of the iron ore is beneficiated by wet process while the other part of the iron ore is beneficiated by the dry process. In the wet process, the feed constitutes hard ore, soft ore and flaky ore, which is fed in pre-determined proportion while in the dry process; feed constitutes of flaky ore and blue dust.
Typically, iron ore separation process involves three stages of separation: cobbing, cleaning/roughing, and finishing. Each stage may employ several drums in a series to increase separation efficiency. Each successive stage works on finer particles as a result of the removal of oversized particles in earlier separations.
- Cobbers work on larger particles and reject about 40 percent of the iron ore as tails.
- Cleaners or scavengers work on particles in the range of 48 mesh and remove only 10 to 15 percent of the feed as tails.
- Finally, finishers work on ore particles less than 100 mesh and remove the remaining 5 percent of iron ore.
The primary wastes from this type of operation are tailings made up of iron ore in the form of coarseand fine-grained particles, and waste water slurry in the case of wet separation.